Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
Sci Rep. 2020 Sep 23;10(1):15560. doi: 10.1038/s41598-020-72119-y.
Less invasive removal approaches have been recommended for deep caries lesions. Antimicrobial photodynamic therapy (aPDT) and propolis nanoparticle (PNP) are highlighted for the caries management plan. Evidence is lacking for an additive effect of combination PNP with photosensitizer (PS) in aPDT. This study aimed to investigate the individual and synergistic effects of chlorophyllin-phycocyanin mixture (PhotoActive) and toluidine blue O (TBO) as PSs in combination with PNP in the aPDT process (aPDT) against major important virulence factors of Streptococcus mutans. Following characterization, biocompatibility of the PSs alone, or in combination with PNP were investigated on human gingival fibroblast cell. The in vitro synergy of PhotoActive or TBO and PNP was evaluated by the checkerboard method. The bacteria's virulence properties were surveyed in the presence of the PSs, individually as well as in combination. When the PSs were examined in combination (synergistic effect, FIC Index < 0.5), a stronger growth inhibitory activity was exhibited than the individual PSs. The biofilm formation, as well as genes involved in biofilm formation, showed greater suppression when the PSs were employed in combination. Overall, the results of this study suggest that the combination of PhotoActive or TBO with PNP with the least cytotoxicity effects and the highest antimicrobial activites would improve aPDT outcomes, leading to synergistic effects and impairing the virulence of S. mutans.
对于较深的龋损，建议采用微创去除方法。抗菌光动力疗法（aPDT）和蜂胶纳米粒子（PNP）被认为是龋病管理计划的重点。目前缺乏组合 PNP 与光敏剂（PS）在 aPDT 中具有附加效果的证据。本研究旨在研究叶绿素-藻蓝蛋白混合物（PhotoActive）和甲苯胺蓝 O（TBO）作为 PS 与 PNP 联合应用于 aPDT 过程（aPDT）时，对变形链球菌主要重要毒力因子的单独和协同作用。在对 PS 进行特征描述后，单独或与 PNP 联合使用 PS 对人牙龈成纤维细胞的生物相容性进行了研究。通过棋盘法评估了 PhotoActive 或 TBO 与 PNP 的体外协同作用。单独以及联合使用 PS 检测了细菌的毒力特性。当 PS 联合使用时（协同作用，FIC 指数<0.5），表现出比单独 PS 更强的生长抑制活性。当 PS 联合使用时，生物膜形成以及参与生物膜形成的基因表现出更大的抑制作用。总体而言，这项研究的结果表明，PhotoActive 或 TBO 与 PNP 的组合具有最低的细胞毒性作用和最高的抗菌活性，将改善 aPDT 的效果，产生协同作用并削弱 S. mutans 的毒力。
